3D Printed Curta Gets Upgrades

It is amazing how makers can accomplish so much when they put their mind to something. [Marcus Wu] has uploaded a mesmerizing video on how to build a 3D printed Curta Mechanical Calculator. After nine iterations of design, [Marcus] presents a polished design that not only works but looks like a master piece.

For the uninitiated, the Curta is a mechanical calculator designed around the time of World War II. It is still often seen used in time-speed-distance (TSD) rallies to aid in the computation of times to checkpoints, distances off-course and so on. Many of these rallies don’t allow electronic calculators, so the Curta is perfect.  The complex inner workings of the contraption were a key feature and point of interest among enthusiasts and the device itself is a highly popular collectible.

As for the 3D printed design, the attention to detail is impeccable. The current version has around 80 parts that need to 3D printed and a requires a few other screws and springs. Some parts like the reversing lever and selector knobs have been painted and digits added to complete the visual detail. The assembly took [Marcus Wu] around 40 minutes to complete and is one of the most satisfying builds we have ever seen.

What is even more amazing is that [Markus Wu], who is a software engineer by profession has shared all the files including the original design files free of cost on Thingiverse. A blog with written instructions is also available along with details of the iterations and original builds. We already did a post on a previous version so check it out for a little more background info.

Thanks for the tip [lonestar]

16 thoughts on “3D Printed Curta Gets Upgrades

  1. 3:1 Curta = So impressive and Gibsonian!
    How long will it be before 3Dprinting can make a 1:1 Curta that is as strong and reliable as the original?
    Is this the start of a timeline that is Moore’s law 2.0 / rod logic?

    1. i think you’d have to SLS print the parts if you want them as strong but idk if SLS can get that small. You could easily print 1:1 using SLA right now but it wouldn’t be very strong.

  2. Just reading the Curta and Curt Herzstark wikipedia pages. [Edit: some offensive language removed — trying to keep the sense of the post nonetheless.] And even those who didn’t escape; Curt designed much of the final Curta as a way to bribe for his life while a prisoner in the Buchenwald extermination prison. Fortunately the war ended before both he and the Curta was finished so no Nazis enjoying Curtas and he went on to live and enjoy the fruits of his ingenious design as did we until the electronic calculators emerged in the 70s.

  3. Fun fact about Curta, In Nazi germany he was a Jew (well Catholic mum, Jewish dad) who found himself at a concentration camp. He offered complicity with the Nazi’s to prolong his life.

    In the end they decided he would make a calculator for Hitler himself and to support the war effort.

    His design wasn’t finished until the US and USSR troops started rolling in so he whisked himself off to Austria and started to actually manufactor the calculators with the help of some VC. Soon the VC wanted rid of him but in the persuit of having him setup as the fall guy they ended up lettimg him walk away with the patents and he finally made it on his own.

    Pretty shitty life, but by being resourceful he seemed to make it though.

  4. A “Gold Standard” to benchmark the fall of the Western World to the Chinese in terms of manufacturing expertise is a Curta Calculator Clone which is almost indistinguishable from the original, and sells on ebay for around $100 USD – with “Free” shipping of-course! It’s only a question of time…

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